1ZET

X-ray data do not support hoogsteen base-pairing during replication by human polymerase iota

Summary for 1ZET

• Entry DOI: 10.2210/pdb1zet/pdb
• Descriptor: 5'-D(P*AP*GP*GP*GP*(BRU)P*CP*CP*(BRU)P*(BRU)P*CP*CP*CP*CP*C)-3', 5'-D(*GP*GP*GP*GP*GP*AP*AP*GP*GP*AP*CP*CP*(DOC))-3', Polymerase (DNA directed) iota, ... (6 entities in total)
• Functional Keywords: protein, dna, dttp, statistical dyad, replication-dna complex, replication/dna
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 3
• Total formula weight: 52823.34

Authors

Wang, J. (deposition date: 2005-04-19, release date: 2005-07-19, Last modification date: 2024-02-14)

Primary citation

Wang, J.
DNA polymerases: Hoogsteen base-pairing in DNA replication?
Nature, 437:E6-7; discussion E7, 2005

PubMed Abstract: Human polymerase-iota belongs to the error-prone Y family of polymerases, which frequently incorporate incorrect nucleotides during DNA replication but can efficiently bypass DNA lesions. On the basis of X-ray diffraction data, Nair et al. propose that Hoogsteen base-pairing is adopted by DNA during its replication by this enzyme. Here I re-examine their X-ray data and find that the electron density is very weak for a Hoogsteen base pair formed between a template adenine deoxyribonucleotide in the syn conformation and a deoxythymidine 5'-triphosphate (dTTP), and that the fit is better for a normal Watson-Crick base pair. As a guanine-cytosine (G-C) base pair has no potential to form a Hoogsteen base pair at physiological pH, Hoogsteen base-pairing is unlikely to be used in replication by this polymerase.

PubMed: 16163299
DOI: 10.1038/nature04199

Experimental method

X-RAY DIFFRACTION (2.3 Å)